Car Stereos: Car radios


Question
I too have just installed a Sony Xplod CDX-GT300, but this time  into a year 2000 Jeep Grand Cherokee Limited, the radio plays great but a cd  has no sound, the player shows that it is playing the cd, but i can't hear anything, I know it works because i had it hooked up in my old car before. What could cause this to happen???

Answer
Hi Roy,

This is actually a very common issue.

When you installed your Sony head unit into your Jeep, you probably used an adapter harness.  That harness has a solid blue wire in it, and you would have connected this to the solid blue wire in the Sony plug.  However, this is incorrect--the blue wire in the adapter harness needs to be connected to the blue/white wire from the Sony plug, not the solid blue wire.

This is because your Grand Cherokee has a factory amplifier as part of the Infinity sound system (you can see the amplifier under the passenger rear seat).  Just like an after-market amplifier, the stock Infinity amp has to be activated before it will produce any sound, and the activation wire is pinned to the blue wire in the adapter harness.

The solid blue wire in the Sony plug is a power antenna output, so when it's used to activate the factory amp, you only get sound when the tuner is selected.  The blue/white wire is the true remote output, and it will keep the amplifier working regardless of the source selected.

The reason this is such a common problem is that harness manufacturers, for some reason, like to use a solid blue wire instead of a blue/white wire for this generation of Chrysler vehicles.  If the harness wire was blue/white instead of blue, it would prevent a lot of problems like yours.

Hope this helps!

Brian